The present invention relates to memory initialization in a set-top box of the type used in consumer/home applications for processing audio/video signals, including signals provided by cable and, more particularly, to software/firmware for providing an improved initialization sequence for flash memory used in the set-top box.
Set-top boxes (STB) are a common electronic device in many homes and are used to process televisions signals provided, for example, from a cable, into various consumer devices, particularly television sets. In general, set-top boxes include signal processing devices to process the particular digital (and/or analog) audio and/or video signals, one or more microprocessors that handle supervisory and control functions, and one or more volatile and non-volatile memories designed to store short-term and long-term information. The microprocessors are controlled by firmware that includes control sequences and sub-sequences for all the functions provided by the set-top box.
An exemplary known set-top box STB manufactured by the Sony Corporation of Tokyo, Japan for the processing of digital television (DTV) signals includes a DTV board that includes, among other devices, a microprocessor and an associated non-volatile memory that stores various user settings and other operating parameters. Additionally, the set-top box includes a front-panel board that includes a register for recording or otherwise storing user command key presses, and, like the DTV board, includes a microprocessor. Lastly, the set-top box STB typically include another board having a tuner and a down-converter.
In the particular implementation described above, user settings and various operating parameters are stored in a non-volatile memory using conventional file system structures. In general, flash-type memories are commonly used as the non-volatile memory. Flash memories are generally of the type in which charges are supplied to or removed from a floating gate in order to alter the threshold characteristics of the memory cell as a way of storing information. These memories are non-volatile in the sense that the individual memory cells retain their memory state when power is removed, need not be refreshed on a periodic basis by refresh circuitry, and all the memory cells can be erased simultaneously by momentary application of selected voltage potentials.
One problem associated with the use of file system structures to hold operating information is that the memory must be correctly initialized in advance of any data writes in order to be usable by the DTV application. The memory must be write-protected against involuntary write operations, and the section of the flash section where the information is to be stored must be appropriately formatted. In general, protection/formatting is performed only once, when the set-top box is turned on for the first time. The above-described set-top box does not both function to initialize the flash memory and thereafter start the DTV application; the flash initialization application and the DTV application are not compatible and cannot be run consecutively. Thus, the set-top box must be subject to a less-than optimal re-set after initializing the flash memory in order to re-start the DTV application.
In view of the above, it is an object of the present invention, among others, to provide flash memory initialization in a set-top box of the type that processes digital television signals that, upon start-up, determines whether or not the flash memory has been previously initialized.
It is another object of the present invention to provide flash memory initialization in a set-top box in which the set-top box functions in its normal signal processing mode where the flash memory has been previously initialized.
It is still another object of the present invention to provide flash memory initialization in a set-top box in which the set-top box effects initialization of the memory when necessary prior to function in its normal signal processing mode where the flash memory has not been previously initialized.
In view of these objects, and others, the present invention provides a flash memory initialization sequence in a set-top box of the type having a program-controlled microprocessor and a DTV board for processing at least part of an audio/visual television signal in which the sequence, upon application of start-up power, determines whether or not a selected file exists indicative of at least a desired partial formatting or other initialization of the flash memory. In the event the selected file exists, the main DTV application thereafter starts and runs normally. Conversely, where the selected file is not detected, the initialization sequence runs an initialization routine that at least formats a portion of the flash memory, thereafter creates a selected file indicative of the formatting of the flash memory, and returns control to re-determine whether or not the selected file exists and to then cause the main DTV application to run.
The present invention advantageously provides a flash memory initialization arrangement in a DTV set-top box that efficiently assures reliable operation of the DTV application.
Other objects and further scope of applicability of the present invention will become apparent from the detailed description to follow, taken in conjunction with the accompanying drawings, in which like parts are designated by like reference characters.